Resistance value of ign wire to coil for Duraspark ign sys.

I'm working through a hard cold starting problem.
460, basically stock, 750 edel.
It won't start after the truck been sitting for a few days,
I know what the problem is. Lousy winter gas here (portland OR) 10+ % ethanol 90% slug piss.
The resistance wire is from the old points ign. and a blue grommet box electronic coil needs a lower resistance value. or a higher running voltage.

For those that have the factory ign, with the autolite ign box.
What is the voltage at the coil with the key ON and engine OFF?
Or can you measure what the exact resistance of the wire? I haven't found a number posted online.

I want to shorten the resistance wire to increase the voltage to the coil.
I believe the coil is getting too low a voltage. at start. ( i don't have a separate start circuit)
the engine will crank and crank and no spark.
as the battery runs down the coil voltage drops too.
The poor gas here, won't light up.
the truck is a 66 and the wiring harness is a 68 galaxie that I took apart and reconfigured to fit the truck.
If the engine is still even a little warm or a little vapor left in a cylinder.
It'll start right up no problems at all.


thanks!!
Dane V
Merry Christmas!!

Try hooking the Duraspark module to 12 volts. If I'm not mistaken, the input voltage directly effects the output amperage. It's pretty much a transformer.

Dave.

It is hooked up to 12v battery.
The setup Ive used on several other cars and different engines is to run the box power off the ign on to the run circuit, not hooked up the start circuit.
resistance wire to the coil.

This winter the truck developed this problem of not starting after sitting for a day or more.
the gas around here is terrible. and the low voltage to the coil on my truck, just won't light up the fuel.
but it will start just fine after it's warmed up it's fine.

danev2 wrote:
It is hooked up to 12v battery.
The setup Ive used on several other cars and different engines is to run the box power off the ign on to the run circuit, not hooked up the start circuit.
resistance wire to the coil.

This winter the truck developed this problem of not starting after sitting for a day or more.
the gas around here is terrible. and the low voltage to the coil on my truck, just won't light up the fuel.
but it will start just fine after it's warmed up it's fine.

If the car is wired correctly, the fender solenoid bypasses the resistance wire to supply 12 volts direct to the coil for starting. So during cranking, you should get full battery voltage on the + side of the coil. Try a jumper wire from the battery direct to the + side of the coil and see if it starts easier. If so then your problem is in the start circuit.

BYW. What is your cranking voltage?

Note also that the Duraspark Module requires (2) voltage sources. Looking at the wire coloring on the module plug, the White wire is energized by the fender solenoid. This retards the timing 10 degrees for ease of starting. The Red wire is energized by the run position on the ignition switch.

Use the older resistance wire of the ignition circuit of an older vehicle to sxite a simple relay.

The DuraSpark does use a ballast resistor during running mode however, it by-passes this resistor during ENGINE START.

This CAN be done with a resistance ignition wire IF there is an ignition by-pass in the start solonoid.